Medical devices such as stents, stent grafts, and vena cava filters are often utilized in combination with a delivery device for placement at a desired location within the body. A medical prosthesis such as a stent, for example, may be loaded onto a stent delivery device such as a balloon catheter and then introduced into the lumen of a body vessel in a configuration having a reduced diameter. Once delivered to a target location within the body, the stent may then be expanded to an enlarged configuration within the vessel to support and reinforce the vessel wall while maintaining the vessel in an open, unobstructed condition. In some medical procedures such as a percutaneous transluminal coronary angioplasty (PTCA), for example, the stent may be deployed and expanded within a vessel adjacent to the location where a lesion has been removed to prevent restenosis or prolapse of the vessel at that region. In some embodiments, the stent may be mechanically expanded by the inflation of a balloon on the delivery device.
Stents which are expandable by inflation of a balloon are typically secured to the balloon of a balloon catheter in a reduced diameter configuration or profile prior to their use. In some techniques, for example, the stents are loaded onto the balloon and then inserted into a crimping device which applies an inwardly directed radial force to the stent to reduce the diameter of the stent around the balloon.
In some techniques, for example as disclosed in U.S. Pat. No. 5,836,965 to Jendersee et al., the balloon material may be heated to an elevated temperature, such as greater than the glass transition temperature of the balloon material, causing the balloon material to soften and thus more easily conform to the contours of the stent. In other techniques, for example as disclosed in U.S. Pat. No. 5,976,181 to Whelan et al., the balloon material may be chemically treated in order to soften the balloon material such that the balloon material may more easily conform to the contours of the stent.
There is an ongoing desire to provide alternative methods and techniques to crimp a stent onto a stent delivery catheter. Furthermore, there is an ongoing desire to provide alternative arrangements of stent delivery systems.